Many astrology novices focus strictly on sun signs when attempting to glean information about astrological compatibility, failing to understand the depth of relationship astrology. There are many factors to consider when examining the potential of a relationship from an astrological standpoint. An astrology chart consists of a sun sign, moon sign, rising sign and eight planets; each planet rules a particular area of life and should be taken into consideration when assessing compatibility between two people. Synastry, also known as relationship astrology, involves the comparison of two astrological charts to determine areas of strength and weakness in a relationship. Synastry is a valuable resource for people who want to examine their relationship with another person based on aspects between each person's birth charts.

In synastry, the interaction between both birth charts is examined, offering an accurate gauge of compatibility. A basic understanding of birth chart interpretation is necessary before attempting to employ synastry techniques because many of the same principles used in birth chart interpretation are also utilized in synastry. Learn the basics about synastry by using the following guide and discover the weaknesses and strengths in your relationship.

Planets and LuminariesThe most important planets/luminaries in synastry are the Moon, Venus and Mars. The Moon rules the emotions and the way each individual responds naturally, making it an important factor in love relationships. Venus rules the love nature and determines what type of partner a person is attracted to. The sex drive is represented by Mars, making this planet extremely influential when determining sexual compatibility.

The Sun and Ascendant are also critical factors in synastry. The core personality of each individual is expressed by the placement of the Sun sign, while the outer demeanor is expressed by each person’s Ascendant. What makes the Sun and Ascendant so important in synastry is that they are more immediately recognizable than any other planets when two people first meet. In the beginning, people are attracted to each other based on the interaction between their Sun signs and Ascendants. It is only after the two people have interacted for a while that the traits of the Moon, Venus and Mars sign become apparent. Basically, the Sun and Ascendant attract two people to each other while the Moon, Venus and Mars determine whether the attraction is strong enough to sustain a relationship.

AspectsConjunction (planets are in the same sign) – This aspect brings two like forms of planetary energy together, amplifying the effect on each. The conjunction is the most powerful aspect in synastry and can produce either harmony or disharmony depending on the planets involved. Too many conjunctions between two birth charts can create tension because the people involved are too similar.

Trine (planets form a 150° angle) – This is the most positive aspect in synastry. The trine creates compatibility and a harmonious blending. Despite the clear compatibility of this aspect, it contains the risk of boredom and repetition in the relationship. The two energies blend together so easily that the relationship may be lacking the passion or urgency accompanied by other, more challenging aspects.

Sextile (planets form a 60° angle) – The sextile creates a harmonious blending of planetary energies and a lasting bond between two people. This aspect is similar to the trine, however, it tends to be more stimulating because the two signs involved are in different elements.

Square (planets form a 90° angle) – The square tends to create stress and tension. Although this aspect generates a compelling and exciting response, it can be challenging. Depending on the planets involved, there may be a strong urge to dominate each other. Too many square aspects between two charts tend to amplify the negative qualities in each person.

Opposition (planets form a 180° angle) – The affect of this aspect is deep and powerful, and sometimes destabilizing. With this aspect, the reverse images of the same energy are brought into contact. This aspect can be likened to a mirror image and creates a strong magnetism. While the attraction accompanied by the aspect may be strong, the interaction is challenging.

Qunicunx (planets are within a 1° - 2° orb) – The energies between these two planets do not blend easily and tend to create a dramatic effect. This aspect is stimulating, however, and produces a competitive spirit between the two people involved. In its extreme, this aspect causes rivalry and bickering.

Important Aspects in SynastryAny interaction between the Sun, Moon, Ascendant, Venus or Mars tends to create a strong attraction between the two people involved. Aspects between Venus and Mars in particular indicate sexual attraction. While harsh aspects between Venus and Mars are more likely to create a strong sexual attraction, they are also more likely to present obstacles and challenges in the relationship. Trine and sextile aspects between these planets create a harmonious blending of energies, however, sometimes the relationship seems too comfortable and excitement may be lacking.

Aspects between the Moon and Venus or Mars indicate whether the two people involved are emotionally in tune with each other. Tense aspects, such as the square or opposition, can put a strain on the relationship, preventing two people from relating to each other on an intimate level. Harmonious aspects, such as the trine or sextile, make the interaction easy and comfortable; the partners usually have enough in common to sustain a relationship and are able to form a deep, emotional bond.

HousesIn synastric analysis, the interplay of houses between two charts determines what role the individuals have cast each other with regard to the planets involved. When comparing birth charts in synastry, planets in the 1st, 5th, 7th and 8th houses are the most important because these houses possess a relationship theme. If some of your planets fall in the 1st, 5th, 7th or 8th house of your partner’s chart or vice versa, an intimate partnership is indicated. Here is a brief explanation of what each of these houses represent in synastry:

1st House (Ascendant) – The image and outer personality are ruled by the 1st house. Attraction takes place when we find another person’s image or personality appealing and desirable. When planets occupy the first house of another person’s chart, it is likely that there is a strong attraction between the two people as well as an approval of the other person’s demeanor and appearance.

5th House – The fifth house rules pleasure and romance. If there are an abundance of planets in the 5th house of one or both charts, a strong bond of friendship and familiarity is indicated. Both people involved find the same activities enjoyable and tend to possess the same likes and dislikes.

7th House (Descendant) – The seventh house rules relationships and partnerships. This house is extremely important in marriage. When one person’s planets occupy the 7th house of their partner’s chart, a successful marriage is strongly indicated.

8th House – The eighth house rules sex. Depending on the planets occupying this house, there may be an urge to possess or control the other person. Depending on which planets are involved, there may also be obsessive tendencies exhibited by the person whose planets occupy their partner’s 8th house. At the very least, there will be an intense, inexplicable attraction towards one another when planets occupy the 8th house.

Through synastry, the complex dynamics of love and human relationships can be better understood. Because nothing so profoundly affects our lives as our contact with others, synastry should be approached with thoroughness and an open mind. In order to obtain an accurate assessment of a relationship, take all aspects of synastry into consideration.

Is Astrology In Your Vocabulary?Do you love reading your daily horoscope, checking out astrology charts, and taking astrology quizzes? Do you rely on astrology to discover more about how to fulfill your needs, achieve your potential, or establish a love relationship? Is astrology your barometer for discovering compatibility? Take this astrology quiz to discover just how much you really know about astrology and the way the stars affect your life.